Parting shots at Dead Crab Mud Volcano

April 22, Tuesday. The last Alvin dive yesterday had its share of close encounters with seamonsters, to be posted here and now before the ship arrives in Gulfport at 2 pm and mundane reality sets in. Here we go!  Alvin is working away, recovering Ian’s camera from the shores of Dead Crab Mud Volcano, when the alien invasion starts, 831 m deep down.Screen Shot 2014-04-22 at 4.16.37 PM

Screen Shot 2014-04-22 at 2.48.03 PMScreen Shot 2014-04-22 at 2.46.51 PMThese little translucent aliens are dancing around the sub and have their pictures taken. They look like transparent swimming crabs with leg appendages and some sort of quickly beating swimming tail studded with fast-moving cilia, and all this capped by a barrel-like transparent tube. A bizarre larva perhaps? Whatever they are, they seem to be attracted by the Alvin lights. Anyway – next comes THIS. Screen Shot 2014-04-22 at 4.21.48 PM

Screen Shot 2014-04-22 at 4.25.33 PMA true Primadonna of a jellyfish cruises up and down in full view of the Alvin cameras, and swims with powerful pumping motions as it ejects water ventrally (I assume) by contracting its body. It is doing loops and turning around so that we can admire its ventral opening, or maw. By the looks of it, I would not be surprised if the tentacles sting.

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Such life forms can only be truly observed in their native habitat. Imagine catching this jelly in a net… only a reddish blob of jam would survive the trip to the surface. The deep sea harbors many biological secrets and will without any doubt keep many of them.

For the next picture, we hope you have already eaten your lunch. A black eel is hanging almost vertically in the water and Screen Shot 2014-04-22 at 4.30.03 PMcarrying something in its mouth that looks like a high degraded fish carcass, perhaps found in Dead Crab Lake. The eel tries several times to gulp it down, but the carcass is hard to handle; finally the eel swims away, its lunch still dangling from its mouth. The movie version is something!

Last but not least, the very place itself – Dead Crab Mud Volcano – is alive. The mud volcano is active and sends fingers of mud crawling over the surrounding deep-sea floor.Screen Shot 2014-04-22 at 3.50.47 PMScreen Shot 2014-04-22 at 3.49.51 PM

Alvin follows the fresh mudflow from shore to the center of the lake and finds a fresh mud volcano crater spewing mud and bubbles. Dead Crab Mud Volcano is undergoing one of its episodic eruptions of gas and fluidized mud. Over time in the last four years, these eruptions must have filled up the lake with mud and pushed its clear brine out. Screen Shot 2014-04-22 at 3.51.17 PM


Screen Shot 2014-04-22 at 2.38.13 PMOver the last few days, since dive 4694, the mud level must have been rising; Ian’s camera was left on the lake shore on solid ground stained black by reducing brine flow, and is now sitting ankle deep in light-grey mud. This mud volcano is very much active and demonstrates seafloor geology in action!Screen Shot 2014-04-22 at 3.45.50 PM

The old coring holes behind the VTLC camera are still visible, but soon they will be swallowed by the rising mud. A timely rescue for the camera … it turns out to have recorded good footage for three full days. The dive time is almost up anyway and it is time to grab the camera and run! Screen Shot 2014-04-22 at 2.26.08 PMNobody wants to share the fate of this fish in the mud volcano who took research a little too far. The gulper eel will be waiting…





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Back in Gulfport: Close of blog

April 22, Tuesday. It is early in the morning and RV Atlantis is near Gulfport. We are close to the 2-hour buoy just south of the Mississippi barrier Islands. This is now a race against time. There is work going and being wrapped up on in the labs until the last minute! By 2 pm Atlantis is docked on the East Pier of Gulfport Harbor, and the great schlepping begins. The U-Haul truck from UGA is big (some fastidious people might call it HUGE) but certainly not too big. Meanwhile the UNC microbiology team has trucked its seven boxes of random equipment to the Fedex office in the afternoon, and the UNC methane and ammonia team has the handy institutional van ready.IMG_7664UHaulApril22


At sunset, the scientists and crew alike are meandering to a local house on the harbor, Big Mike’s Speakeasy. The place has a certain reputation from previous cruises. “They treat us well!” The wide lawn in front is a souvenir of hurricane Katrina that cleared out the waterfront of Gulfport.IMG_7669MikesSpeakEasyApril22 Insurance agents of all port cities, pay attention!

And then there was general rejoicing. On land again, with a cool beer (or else) and in the company of one’s fellow adventurers and assorted landlubbers who bask in the presence of these fearless explorers! Tall tales get taller, the tabs get longer and longer, and who knows where this will end. IMG_7676PartysceneApril22Life is short but science never ends…

We have the most interesting discussions on the logistics of The Burning Man Festival, the sociodynamics of Russian-German Antarctic expeditions and irregular Wodka supply, the most authentic and frightening pronunciation of german-derived family names among the Alvin crew, the absolute necessity of Alvin exploration of the unexplored seafloor (it is so much more exciting than those slick ROVs, and has an existential and religious dimension: once your dive time on the lowly seafloor is over, you rise and you shall be judged based on what you accomplished), the acute awareness that every Alvin dive might be your last given current NSF funding (and the beer list of this place), and and and. At some point it is best to stop and to stumble back to the ship. Tomorrow is another day. We close this blog and thank the readers, the funding agencies NSF and GOMRI, the RV Atlantis crew who have made all this possible, and the tireless Alvin crew who are perfecting the new Alvin and raise a new generation of superb Alvin pilots and engineers as you are reading this.

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Dive 4702: Last call at Dead Crab Mud Volcano

April 21, Monday. Today is our seventeenth and last dive in twenty-two days; after much strategizing, the choice was Dead Crab Mud Volcano. It has a lot of unfinished science attached to it, it is not too far from Gulfport and therefore allows a speedy return trip in time for tomorrow before noon, and – last but not least – one of Ian’s VTLC cameras is still at the bottom and recording the competition between brine flow and mud volcano eruptions. The dive team of last resort is Rick Peterson of Coastal Carolina University and Joy Battles of UGA, and the sub is piloted by Bob WatersIMG_7599Rick&JoyApril21.

Here they smile determinedly at Ian’s camera. By now it is early afternoon, the news from the sub are good, they are busy mapping the place and going through the 10 items on their shopping list. When they return, we will all burst into frenetic activity; the sub has to be secured, the ship starts steaming to Gulfport instantly, and the cores and samples have to be worked up to some intermediate and portable stage.

In the meantime, I am visiting places on RV Atlantis. Today is the perfect opportunity for a visit to the rad van, where Vladimir and Ryan have been shooting up radiotracer samples to measure microbial process rates (methanogenesis, methane oxidation, sulfate reduction, alkane oxidation) for much of the cruise. This is a special place. One has to follow convoluted paths to the front deck, find the secret door, enter, and say hello.


Who is knocking at the door and asking for entry into this secluded oasis of clean and meticulous science? Do not worry, Vladimir and Ryan are soon all smiles and happy to explain the secrets of their art, like the auto-adjustable isobaric incubation device made from a simple hungate tube that translates hydrostatic pressure outside of a vial into the microbial incubation on the inside by means of a movable rubber stopper.


Meanwhile, Alvin returns from its last dive on this cruise and is scrubbed thoroughly with the sideboards removed. A rare opportunity to see how Alvin is stuffed to the gills with ballast tanks, pumps, electrical and propulsion systems.



Not to forget, Joy is inducted into the Alvin Dive Hall of Fame in classical style. It is a hot afternoon and the refreshing ice shower is perhaps not so unwelcome.


The dive was very successful and returns with lots of sediment cores, lots of mussels, Ian’s VTLC camera that was semi-accidentally forgotten on the shores of Dead Crab Mud Volcano the last time, a large seafloor photo mosaic of the Dead Crab area (the bottom camera works this time), one of the three temperature loggers left there in 2010, and last but not least brine samples. The entire shopping list is checked off – impressive by any standards!


As soon as Atlantis is secured on deck, RV Atlantis is ramping up its engines and we are on our way to Gulfport with 13 knots in flat calm seas. We celebrate the return to the rest of the world with a spontaneous sunset party.


Swallows are following the ship; they must be on their way north, towards the juicy bugs in the Louisiana saltmarshes, and then up the Mississippi flyway. Allison is feeding them with mealworms and they are quite happy about that.


Tomorrow in Gulfport. The Great Packing Event will begin!



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Dive 4700 special: Orca Basin Knife Edges and Cliff Faces

Sunday, April 20. The dive footage from yesterday’s Dive has been released, and the footage of the colorful cliff formations and glass sponges was so spectacular that a special is called for.  Early on this dive, Alvin encounters a pink and purple escarpment with downward streaks of briny outflow and mineral precipitaion; the sub parks in front of the steep slope, and starts coring into the color-coded sediments.Screen Shot 2014-04-20 at 7.37.24 PM

The upper edge of the cliff face and the overlying sediment are cored with the starboard arm; some cores go directly into the steep cliff face – analogous of coring the Eiger Nordwand from a dirigible. Others come in vertically from the top and capture the strongly sloping sediment stratification. These Alvin screenshot show how the cores are pushed into pink slope at a 45-degree angle, Screen Shot 2014-04-20 at 5.36.02 PMwhile Alvin hovers above the slope.Screen Shot 2014-04-20 at 5.35.16 PMThe colorful sediment formations demand to be captured on beastcam. In a drama that only the digital boards of the beastcam could fully tell, the camera manages to take just one picture before expiring ! Orca Basin is perhaps a bit much and the camera might have felt overwhelmed. But that picture alone was worth it – it shows the fine millimeter-scale sediment laminations just below the surface sediment cover that are also visible in Core no. 19 collected right here at this spot on this dive, my personal favorite., and the colorful minerals that (probably) mark brine oIMG_0001utflow on the slumping slope a little deeper down.

After collecting pink cores from the escarpment, sponge collecting begins on the more level surface nearby. Elegant tube-shaped glass sponges dominate here, and the Alvin arm seems to bow in reverence as it prepares to gently lift a specimen out of his home habitat and into the great Alvin spaceship, the alien craft sent by the surface biosphere sentinels.Screen Shot 2014-04-20 at 6.39.17 PM


Screen Shot 2014-04-20 at 7.52.10 PMThe sponges look like beautiful otherwordly creatures in their native habitat; fragile and slow-growing organisms that are finely adapted to the slow-motion world of these deep waters. The increasing salinity and decreasing oxygen so close to the chemocline introduce additional environmental selection factors that may keep other life forms out. The specimens that we harvested were sorry to look at in the cold room. Many deep-sea treasures are best appreciated in-situ!

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While looking for more sponges and coring a sponge garden core, an even more dizzying diapir wall appears Screen Shot 2014-04-20 at 8.03.12 PMstarboard ! The sponges are growing on its smoothly sedimented slope that suddenly breaks away into this rugged multicolored cliff face wall that speaks of erosion and dissolution… and the sponge garden core (No. 11)  collected here turns out to be right at the knife edge where the sponge garden sediment drops off to the sheer cliff wall. Screen Shot 2014-04-20 at 8.04.34 PMThese diapir cliff walls may not be very stable; small sediment fans are spreading downward from the knife edge (nicely visible of the screenshot right) and indicate how this slope and its sediment cover must be slowly eroding while the salt diapir is dissolving. The dive video shows the stunning scale of these diapir walls; a camera turn from portside to starboard and back shows a Yosemite- scale mountain landscape of downward-streaking, multicolored brine flow formations scouring and incising the diapir walls. Since an entire hillside of this diapir seems to have dissolved, crumbled and fallen away over time, Halfdome diapir would be a good name.Screen Shot 2014-04-20 at 8.02.43 PM

Alvin shudders deep in its electronic entrails, flies over, hovers in front of the cliff face, and takes cores horizontally from the cliff face, in pink and white. These are the two last cores of the dives and they conclude this visit to the source of the brine in Orca Basin.Screen Shot 2014-04-20 at 7.59.24 PM

Reflecting on the vast range of extreme habitats and research challenges – the massive chemocline where different biota and physicochemical regimes are extending over more than 100 meters, the hypersaline sediments at the deep bottom in different mineral colors, the accessibility limits of the deep basins for anything that floats (like Alvin), the sponge gardens around the rim and on the salt diapirs, and the enormous multicolored eroding cliff faces of the slowly dissolving diapirs  – Orca Basin has to be ranked as one of the truly epic places in the Gulf of Mexico. If the cruise ended right here, we would be content.

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Dive 4701: The Hot Site

April 20, Sunday. Happy Easter! There are stories about a very early Easter egg scavenger hunt at 3 AM in the main lab, but no photos survive. So we start again with the classic Alvin dive photo. We have left Orca Basin and are ready something totally different. IMG_7568Lindsay&MandyApril20Mandy and her postdoc Lindsay Fields are diving today to a special and highly active mud volcano, The HOT site. In contrast to so many other brine lakes and mud volcanoes in the Gulf of Mexico that have temperatures barely above ambient seawater, this one is really hot – temperatures of 40 to 45C have been measured.

IMG_7572Lindsay&MandyWaweApril20From our last visit in 2010, I remember talk and Alvin footage of bubble curtains and huge mud flows; this should be a monster of a mud volcano. Mandy and Lindsay wave intrepidly, if such a thing is possible.

The new Alvin cameras give a vivid impression of this place – a collection of mud volcanoes that are emitting finely dispersed, fluidized mud onto the seafloor. The constant churning of the mud, the unstable surfaces and steadily ongoing sedimentation of fresh particles select against the typical cold seep fauna that needs a minimum of solid ground. Alvin first visits a smaller crater with a bank of soft mud that is easy to core. Screen Shot 2014-04-21 at 4.35.28 PMAlthough methane bubbles are quite frequent and indicate an abundant supply of reducing seep fluid,  there is no sign of microbial mats anywhere; they do not gain a foothold where the seafloor is constantly impacted by mud volcanism. An important detail: Alvin has to be positioned with the current to make sure the mud flow is wafted away from the sub.Screen Shot 2014-04-21 at 4.45.51 PM

After coring is finished, Alvin is following a stream of turbulent mud to its source. This is not longer one of the cute pocket mud volcanoes at Dead Crab Lake… instead, churning mud is flowing from a cleft in the ground, or from a deep incision in the gradual slope of a mountain. This place of constant fluid and mud mixing with seawater is the opposite to the stable chemocline of Orca Basin. The chemical conditions may be less extreme,  but the physical setting prevents sessile benthic life.

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The churning mud is surrounded by terraced sediment banks that look like a series of retreating steps. Are they formed as well as eroded by a series of major eruptions?

The VTLC camera is placed into the trench to observe mud volcanism up close. Since the turbulently flowing mud stays mostly close to the seafloor (it may be weighted down by some extra salt), it should actually be possible to see something in the camera footage.Screen Shot 2014-04-21 at 4.53.32 PM

Only further away form the center of the mud turbulence has a microbial mat established itself. This nice specimen is being cored; in the shipboard lab it turns out that the mat consists mostly of filamentous sulfur produced by sulfide-oxidizing bacteria of the epsilon-proetobacterial genus  Arcobacter, specialists for living in highly recducing turbulent flow. Screen Shot 2014-04-21 at 5.01.42 PMArcobacter oxidize sulfide to elemental sulfur, which they “excrete” in sulfur strings and bundles; the single-celled bacteria are finally only a minority in the mass of accumulating sulfur spaghetti. No Beggiatoa mats this time at the Hot Site … mats are not always what they seem.

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Dive 4700: Cores from Grand Salt Diapir

April, Saturday 19. The weather stays beautiful and calm, and Alvin is getting ready for a PIT dive into the source of the saltIMG_7530GettingAlvinHookedApril19 region of Orca Basin. Here Pat Hickey is hard at work to get the big A-Frame loop around Alvin’s lift-off hook. Watching the proper procedure of an Alvin launch is getting ever more interesting! Jefferson Grau is the Pilot-in-Training, Pat Hickey is the Pilot teacher, and Rich Viso of Coastal Carolina University is the science observer destined for greatness today.


Rich wears the proper shade of Carolina Blue. Who will ever again say something against Marine Science in Myrtle Beach ?

Until 3:30 pm, we hear nothing from the sub; no news is good news! It turns out that the Alvin inmates are busy dealing with oil leaks that disable the portside (left) sampling arm. PIT Jefferson has to use the starboard (right) arm to reach as far as possible across the basket, to pick up cores from their quivers on the far left, and to put them back again. Don’t try this at home! He later calls it good sampling practice… not to mention that some of these cores go into the sheer cliff faces of Grand Salt Diapir.


But the reduced load that Alvin has managed to sample with the “wrong” arm arrives at the surface in good shape. No wild methane outgassing from these hypersaline cores!  The seas are smooth, and the Alvin recovery team (with recovery swimmers Ronnie and Neumann who did the hairy rescue on Thursday) has a pleasant outing. Meanwhile Barbara the core czarina – in blue Howlingbird Shirt –  is enjoying the sun and a little chat with her UNC compatriots.  She is carrying the core sheets as emblem of her authority.


Howard, on the left with blue hard hat and life saver, has become a de-facto member of the Alvin launch and recovery team, and he is indispensable to get the sub’s basket ready in the morning and to get the samples and basket gear off after each dive; remember, he is the Alvin basket czar. But what does the Alvin basket offer today?


The color of the day is pink – the pink of the Orca Basin sponge garden sediments and salt diapirs. Mandy has done some internet sleuthing and found out that certain anhydrite minerals with metal impurities come in nicely matching shades of pink, whereas pure CaSO4 is just IMG_7560PinkCoreIIwhite. Orca Basin brine contains Fe and Mn in the 100 micromolar range, the sediment porewater has a lot of Ca2+, and sulfate is also abundant in the brine (ca. 1.5 x seawater concentration), so – why not?

Normally I don’t post core pictures on this blog since they are of specialized interest only, but these cores are spectacular beauties. Taken from the steep salt diapir slopes, they show alternating layers of different-colored minerals that have formed during different stages of the brine flow. Here is Number 19, my personal favorite.


This I have never seen before – millimeter-fine pink lamination in a sediment core. This core will remain untouched by geochemists and microbiologists, and is set aside for fine-scale mineralogical analysis.

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Seamonster and Sunset

April 18, Friday. Today’s dive break is used productively by CTD sampling of the immense Orca Basin Chemocline – definitely the Goetterdaemmerung of all chemoclines – and with the deployment and recovery of an instrument that I see here for the first time in action, the MOCNESS or Multiple-Open-and-Close-Net-Environmental-Sampling-System.

IMG_7484MOCNESSApril18This sophisticated towed sampler catches anything floating in the water column through a series of windows with long tube-like nets attached; the windows open and close at different times and water column levels and direct the catch of the day to different sample collector binIMG_7487MOCNESSREcoveryApril18s. Launch and recovery of such a large instrument require skillful coordination between crane operator and deck crew. The scientists are staying out of the way until everything is safely on deck.




Joe Montoya is reaching for the sample catcher that has collected everything from this MOCNESS deployment. The plankton container has caught something remarkable and eye-catIMG_7499AllWatchApril18ching; Joe presents the find to the recovery team. It’s biology! Does it bite or sting? It is a Pyrosoma, a planktonic colony of translucent ascidians that grow as a floating tube in tropical and subtropical waters; the individual ascidians are visible as nobs on the tube. Pyrosoma can grow quite long, up to several feet, and they fluoresce in the tropical night – therefore the name, meaning fire body. Although they look strange, as ascidians they are our distant cousins –  long ago in the Precambrian, they turned towards the road not taken by our chordate ancestors.


The catch of the day turns out to be an amazing marine plankton soup of innumerable small animals and organic particles from the upper water column; the idea that ocean water is a kind of highly dilute chicken soup with abundant small-scale organic material and metabolic hot spots around floating particles becomes all of a sudden tangible.


This evening we have a spontaneous sunset party on the aft deck. With our crazy weather, nobody has seen a decent sunset in quite a while. Now all what we need are margaritas and tapas and some cool jazz. A cold beer would also do nicely.IMG_7509SunsetPartyApril18


IMG_7517SunsetApril18Three more dives… this eventful cruise is slowly coming to a close. We turn our thoughts to wrapping up work, packing and shipping, and of course to returning home again. That does not need special prodding…



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